Garrie - again, many thanks for your thoughtful, thorough reply and
observations.
I think the only one I would question is the brain size - I
believe you are citing the size of the adult brain. An infant's brain
size is much smaller. So delivery of the infant at birth might not be
nearly the problem you think. Also, at birth is the head the largest
object, or is it the shoulders or the hips?
You are quite right about natural selection preferring nothing -
it has no preference. It just describes the result of a natural
process, as you point out. Jim
On Jul 19, 12:52 pm, GarrieMushet <[email protected]> wrote:
> Jim,
>
> In evolutionary terms, the most important goal is to hand down your
> genes. The prerequisites to this goal are reproduction and survival.
> Therefore, there is NOTHING more important than survival in
> evolutionary terms.
>
> So no, I wouldn't say that sleep serves a purpose more important than
> survival. I would say that sleep serves the purpose of survival, in
> fact.
>
> You are entirely right that sleep makes the sleeper vulnerable to prey
> that is not asleep. But natural selection does not know this.
>
> Many people see evolution and natural selection as independent
> conscious agents who constantly and actively refine the organism to
> make it better and better at surviving. This just isn't the case.
> Natural selection and evolution aren't 'aware' of anything. They do
> not know that sleeps makes up vulnerable. I daresay that if evolution
> and natural selection were conscious creative agents, then sleep would
> have been abolished long ago.
>
> It hasn't though. Why? This is your question, I believe. Why haven't
> we evolved to not require sleep, when in fact, it is a danger to the
> organism to be a sleep.
>
> Well first of all, let me say that sleep is not the only phenomenon of
> living creatures which would seem to be a disadvantage to individual
> survival. Let me introduce to you a few of them within our own
> species:
>
> 1) The human brain.
>
> Around 2 to 2.5 million years ago, our ancestors had brains with a
> volume of only 400 cubic centimetres. Around that period, it bloomed
> to about 650 cubic centimetres. Around 500,000 years ago, it jumped to
> 1,200 cubic centimetres. And then around 150,000 to 200,000 years ago,
> when the first 'homo sapiens' walked the plains of africa, it jumped
> to its current volume of around 1,400 cubic centimetres.
>
> But the problems that came from the increase in the volume of the
> brain were quite substantial. For starts, millions upon millions of
> women have died in the last 200,000 years because their pelvises have
> been unable to pass the head of a baby needed to house this massive
> organ. Quite a lot of the time, the baby perished too.
>
> Not only that, but the brain takes up one fifth of the entire human
> energy reserve. So 200,000 years ago, our ancestors found themselves
> having to hunt and eat a lot more food than they had to when their
> brains were only 400 cubic centimetres.
>
> Our heads are now so heavy that the risk of a human suffering from a
> broken neck is massive compared to that of our chimpanzee cousins.
>
> 2) Walking on 2 legs.
>
> Humans still haven't adapted to walking to 2 legs as fully as they
> could be. Walking on two legs is a relatively recent practice among
> the species, and as such, we haven't quite had the chance to
> assimilate to it. The statistics for the number of humans with chronic
> back problems are enough to convey this, and almost every single human
> will have personal experience of it at one point in their lives. Going
> back 200,000 years, the notion of back trouble was even more daunting
> than it is today. For us it means annoyance when rising from our
> chairs, but for our ancestors it was the difference between escaping
> predators and being gored to death. It was the difference between
> catching the extra prey necessary to provide the energy that our
> brains required and lying on the african plains, dying from
> starvation. It was the difference between between being sexually
> attractive and sexually selected, and being cast aside to die without
> ever passing on their genetic codes.
>
> So why oh why has natural selection not ridded us of these burdens?
>
> Well, because Natural Selection really doesn't care. Natural selection
> is indifferent to what makes us vulnerable. Natural selection has no
> inclination to remove the characteristics which cause us great pain
> and discomfort. Natural selection doesn't care if we live or die.
> Because natural selection isn't capable of caring, or thinking, or
> realising what characteristics are beneficial, and which are
> burdensome.
>
> The reason we continue to sleep, walk on 2 legs, and have massive
> brains is the NET effect they have on us, as a species, is a
> beneficial one. So although, if you look at sleep from one angle, it
> seems to be a great disadvantage, if you look at it from another
> angle, you see that the benefits we gain from it far outweigh the
> disadvantages.
>
> Afterall, sleeping for 8 hours a day only makes us vulnerably for 1
> third of our lives, but it keeps us fresh and awake and able to escape
> predators and catch prey for 2 thirds of our lives. If we never slept,
> the nature of our physiology would make us vulnerable for 100% of our
> lives (and short lives they would be!).
>
> In conclusion:
>
> Yes, many organisms have died from being asleep at the wrong time,
> having massive brains, and attempting to walk on two legs. But many
> more organisms have USED their brains to aid their survival, have USED
> their walking habits to benefit their survival, and used a good
> night's rest to make them must more 'fit' for an overwhelming majority
> of their lives.
>
> On the whole, these characteristics have been beneficial enough to
> allow the majority of the organisms that have these characteristics to
> survive, reproduce, and hand those characteristics down to their
> offspring. And the humans who refused to walk on two feet, didn't have
> as big brains, or didn't get enough sleep perished in the competition
> of their smarter, faster, and more energised rival humans.
>
> Natural selection doesn't refine us until we are perfect. It just gets
> rid of the specimens whose genes do not allow them to survive to pass
> them on.
>
> Regards,
>
> Garrie
>
> On Jul 19, 7:51 pm, retiredjim34 <[email protected]> wrote:
>
>
>
> > Garrie - on further reflection, is seems to me self-evident that sleep
> > makes the sleeper vulnerable to a predator that isn't sleeping. So
> > since virtually all living forms sleep, sleep must be needed for some
> > reason more important than survival. Does that sound right? Jim
>
> > On Jul 18, 10:24 am, retiredjim34 <[email protected]> wrote:
>
> > > Garrie - Excellent point. Thank you. Jim
>
> > > On Jul 17, 4:45 am, GarrieMushet <[email protected]> wrote:
>
> > > > If sleeping was dangerous enough to kill all animals that need lots of
> > > > sleep, then indeed, those animals would have died out. But they
> > > > didn't.
>
> > > > The fact of the matter is that most animals who sleep did NOT die out,
> > > > and therefore they WERE able to survive and reproduce.
>
> > > > So rather than thinking that the theory of evolution is wrong based on
> > > > your hypothesis that sleep isn't compatible with naturally selected
> > > > highly evolved beings, I would tend to think that your hypothesis that
> > > > sleep isn't compatible with naturally selected highly evolved beings
> > > > is flawed.
>
> > > > There are many examples of features and characteristics that have
> > > > evolved that increase the risk of death. But as long as this risk of
> > > > death does not kill people too early, then they have time enough to
> > > > reproduce, and their traits will be passed on.
>
> > > > These are not exceptions to the theory of evolution, they are simple
> > > > traits that, whilst they may decrease the quality and length of life,
> > > > they do not do so enough to reduce the chances of reproducing. If they
> > > > did, those characteristics WOULD have died out.
>
> > > > On Jul 14, 6:35 pm, retiredjim34 <[email protected]> wrote:
>
> > > > > As I understand one basic premise of the theory of evolution,
> > > > > survival of the fittest prefers individuals that live longer, breed
> > > > > faster and leave more progeny. Yet two traits we possess – sleep and
> > > > > intelligence – seem to contradict this preference.
> > > > > Sleep works against survival for, while sleeping, an
> > > > > individual can
> > > > > hardly defend against attack and consumption. So evolution would seem
> > > > > to have selected those individuals needing less and less sleep, until
> > > > > sleep would no longer be needed. Yet today, maybe one billion years
> > > > > after speciation began, we still need our 8 hours of sleep.
> > > > > Intelligence also seems to disprove the all-encompassing
> > > > > scope of
> > > > > evolution. Those individuals better able to recall experience and
> > > > > predict the future would have an advantage in food-gathering, mate
> > > > > selection and progeny protection. Yet we hardly seem smarter today
> > > > > than humans living thousands of years ago.
> > > > > Are these traits exceptions to evolution? Are there other
> > > > > exceptions?
> > > > > I expect so. But no one discusses them. Why not?- Hide quoted text -
>
> > > > - Show quoted text -- Hide quoted text -
>
> > > - Show quoted text -- Hide quoted text -
>
> - Show quoted text -
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